This invention relates to a bimetallic terminator for making electrical connections and more particularly to a terminator formed from copper and aluminum members for interconnecting a solid copper conductor rod to an aluminum or copper cable within a separable connector used for high voltage networks.
The problems inherent in the forming of an electrical connection between an aluminum member and a copper member are well known to those skilled in the metal-joining art. Dissimilar metals such as copper and aluminum do not normally form good electrical bonds since such bonds normally have high electrical resistance. Further, the bonds formed between copper and aluminum members are usually weak in their mechanical properties.
It has been disclosed in U.S. Pat. No. 3,566,008, issued to L. F. Ettlinger et al, Feb. 23, 1971 and assigned to the same assignee as the present invention, that a secure mechanical joint having good electrical characteristics may be formed between copper and aluminum members. Sufficient heat and pressure is applied to a tin-plated copper member with chamfered holes therein causing extrusion of the aluminum member into the chamfered holes. While this joint may provide desirable mechanical and electrical joints between the members, it would be desirable to obtain secure mechanical and electrical connections between the copper and the aluminum members without the use of chamfered holes and without the need of a tin-plated copper member.
It has been further disclosed in U.S. Pat. No. 3,916,518, issued to B. J. Jones et al., Nov. 4, 1975, that an aluminum member may be secured to a copper member to form a one-piece bimetallic terminator by an inertia welding process. The aluminum and copper members are rotated relative to each other and are joined together by a rotational inertia welding process along the area of contact between the face of the aluminum and copper members. It is considered desirable to provide a bimetallic electrical terminator that is formed without the use of a rotational process. Furthermore, it is also desirable that the connecting joint between aluminum and copper members be internally positioned within the connector so as to reduce corrosion effects between the copper and the aluminum joint that may be caused by exposure to the atmospheric environment.
It is therefore one object of this invention to provide a copper and aluminum bond which is shielded from the atmospheric environment by a bimetallic connector housing.
Another object of this invention is to provide a method, not using rotational means, for forming the bimetallic connector.
A still further object of this invention is to provide a bimetallic terminator, formed from non-plated aluminum and copper members wherein the aluminum and copper members are bonded and mechanically locked together by a heat and pressure process.
A further object of this invention is an aluminum to copper interlocking connection that has good electrical conductivity and good mechanical strength.